The Subnuclear Structure of Matter - Baryon Spectroscopy at ELSA

One of the open challenges in subnuclear physics is to understand the non-perturbative regime of Quantum Chromodynamics, including the world of the nucleon and its excitations. The investigation of the formation and decay of baryon resonances made of the light quarks up, down and strange is the main topic of the experiments at the electron accelerator ELSA. While the underlying gauge theory, Quantum Chromodynamics(QCD), is well established, the non-perturbative phenomenon of structure formation - the fundamental fields (the quarks and gluons) only appear within bound states (mesons and baryons) and their excitations - is not yet understood. After an introduction into the world of excited baryons and baryon spectroscopy, this talk will focus on the baryon spectroscopy results obtained with the CBELSA/TAPS experiment, including in particular double polarization experiments.